This release updates firefox to 38.7.1. Mozilla decided to disable the Graphite library in this release and we are taking the same action: irrespective of the security slider settings the Graphite library won't be used for rendering fonts in Tor Browser 6.0a4-hardened. The Graphite font rendering library was already disabled for users on the security level "High" or "Medium-High".

Note: There is no incremental update from 6.0a3-hardened available due to bug 17858. The internal updater should work, though, doing a complete update.